Authorities have focused attention in the secret recording case of Senator Mitch McConnell and his campaign team on two liberal activists with a group called Progress Kentucky. NBC's Chuck Todd reports.

A local liberal group has become the target of scrutiny in a probe into the surreptitious recording published earlier this week capturing a campaign strategy session with Sen. Mitch McConnell’s re-election team.

A local Democratic Party official told NBC News Thursday that two members of the activist group Progress Kentucky claimed that they were responsible for a recording published this week on the website of the progressive magazine Mother Jones. In the audio, McConnell is heard discussing with his staff opposition research into potential Democratic challengers, including the actress Ashley Judd.

"They told it to me right when it happened," said Jacob Conway, a member of the executive committee of Louisville and Jefferson County Democratic Party, in reference to two Progress Kentucky officials.

Conway said Shawn Reilly and Curtis Morrison -- founders of Progress Kentucky, a liberal, anti-McConnell group unaffiliated with the Democratic Party of Kentucky -- told him that day, Feb. 2, "that they got this McConnell recording. They told me because of the tackiness and the horrible things that McConnell was discussing. ... That is why I think they recorded it."

But a lawyer for Reilly said he is denying that he was involved.

"Other than acknowledging we were in the building, we completely disavow his characterization of those events," attorney Annie O'Connell said.

O'Connell described Reilly as a "witness" and was cooperating with the FBI.

"On the day that Mother Jones released the recording, our client met with the U.S. Attorney here in the Western District of Kentucky with the lead FBI investigator," O'Connell said. "Mr. Reilly has provided information in the FBI's efforts to locate Curtis Morrison. Our position is that Mr. Reilly is innocent of any wrongdoing. He is simply a witness, not a suspect. What we're saying is Shawn was in the office building that day, but was simply a witness to what happened."

Local NBC affiliate WAVE in Louisville spotted Conway Thursday afternoon entering and leaving the local FBI office to be interviewed for their investigation.

It is illegal for someone to wiretap or bug a room and record a conversation to which they are not a party. Kentucky, like most states, is a one-party state. In other words, if one of the people involved in the conversation recorded it, that is allowed. Illegal wiretapping is punishable by up to five years in prison and a fine of $250,000 for individuals and $500,000 for organizations.

But it is a murkier legal area if someone is in a hallway, for example, and overhears a conversation. Provided an individual is not trespassing, recording something that can be heard by the naked ear, is legal. But using a device to amplify sound that would not otherwise have been heard by the naked ear is not.

Separately Thursday, the treasurer of Progress Kentucky confirmed to NBC News that he had resigned from the group following the publication of the audio.

Douglas L. Davis, the group’s now-former treasurer, would not comment as to his precise motivations for quitting.

"At this time based on advice of both friends and counsel, I will be not be making a public statement available until everything has been reviewed by an attorney at this time," Davis told NBC News. "I have resigned my position as treasurer and did not and do not condone any allegations of illegal activity that might have taken place."

Asked directly if Reilly and Morrison are responsible for the taping of the strategy session, Davis paused, and said, "I can't comment."

NBC News has reached out to Morrison multiple times by email and phone, but he has not yet responded.

The revelations come as federal investigators begin an investigation into the source of the audio recordings. McConnell’s re-election team has publicly suggested it was the victim of a bugging operation, and McConnell pointed the finger at Progress Kentucky.

A source familiar with the investigation into the leaked McConnell audio told NBC News that the FBI had collected surveillance tape from the building in which the McConnell re-election campaign is headquartered.

The Republican Kentucky senator's re-election team has taken this as a sign that federal investigators are more actively probing the possibility that someone outside of the meeting captured on tape was responsible for the recording.

Conway, the local party official, said he has only now come forward to help disassociate the Democratic Party with any actions alleged of Progress Kentucky, especially given that Democrats in the state have a slim majority in the legislature.

"I don't want the party to be associated with this," he said.

Conway called Reilly and Morrison generally "well-intentioned." "I don't think they had sinister motives,” he said. “They were there, were inexperienced, and got excited."

Progress Kentucky has a contentious history with McConnell this election cycle. Earlier this year, the group leveled criticisms of McConnell based on the ethnicity of his wife, former Secretary of Labor Elaine Chao.